As usual, the level is way up there. Just 4 pages, but tells so much.
EDIT: To those who don't get it - He is poisoning her to get adopted into the family as a male heir after her death. She's probably the only child, and this was a common practice back then in Japan to ensure a male heir in the family. What the last panel means is up to the interpretation of the translation which is rather unclear -- could mean that he decided to stop giving her the poison, or maybe they're just discussing on how to continue.
The ending left me thinking that the two guys weren't talking about murdering Oiwa, but rather discussing how the poison was going to slowly kill the Cancer that's growing on her face and while her body would remain unaffected from the effects, the price would be her remaining good looks. That's all speculation on my part though.
This story is based of of a old Japanese play, Yotsuya Kaidan.
See - http://en.wikipedia.org/wiki/Yotsuya_Kaidan
Like Shanzenkou said, back then, the samurai were an elite class. To be a samurai who was serving under someone back then meant you received land rights from him, the peasants who worked that land paid you for allowing them to farm there, and you were automatically better than the commoners. To marry into a land owning samurai family was a huge deal. You would acquire the land that that family owned and you would then be free to parcel out land to your own samurai who would serve you.
In this story Iemon is poisoning Oiwa to get her land. As long as she's alive he can't have her land. So he's using a slow acting poison, one that will kill her after they get married and give him a legal claim to it. Unfortunately it messed up her face before anything else.
The ending is vague. It's most likely that they're discussing still going ahead with poisoning her, but with a smaller dose than before, so the poison won't affect how she looks on the outside anymore, but will still continue to accumulate on the inside.
@belxebu Yep. He's casually eating the hamburger steak but only when she tackles him does he loose it.
Guys, the ending is that the poison they used wasn't fast acting enough to kill her internal organs first, so her face took the damage. There gonna another dosage that will hopefully kill her faster, but not to fast.
I think what gives the ending away is the poisoner's expression on the last page. When discussing the murder he is grinning and enthusiastic. Since his mood shifts to being serious and reserved I believe the plan has changed and the girl won't be killed.
wait then what's with the 'ghost' tag? she hadn't even died
wait might this be an alternative of the 'yotsuya ghost story' mentioned in the title the girl died, with that deformed face, that stringy hair, in a white dress and from then she was only renowned as the stereotypical oriential ghost girl